Previous systems for monitoring liquid intake have enabled liquid intake to be generally determined, or determined on average, exclusively on the basis of an amount of liquid supplied to or removed from the container. To this end, the container may be placed upon a coaster, e.g., within which the evaluation is performed. However, in this manner it is not possible to determine liquid intake in a manner that is specific to an individual. Also, the system is highly prone to errors since the glass is placed next to the coaster inadvertently or due to forgetfulness, for example, e.g., with elderly people, and therefore, accurate filling-level information of the glass cannot be consistently determined.